Datapack JSON

Author recipes, advancements, and tags using Minecraft 1.21.1 JSON and paths. This baseline stays fixed when new output targets are added. The plugin supports a subset of that format, unimplemented fields and triggers require a native override.

The net.rasanovum.rosetta.data Gradle plugin generates resources for the explicitly supported targets: 1.20.1, 1.21.1, 26.1, 26.2, and 26.3. Unknown versions fail instead of inheriting an unverified schema. Loader choice affects override selection, ordinary vanilla JSON uses the Minecraft version.

Applying the plugin

Apply net.rasanovum.rosetta.data to each target project. Define recipes, advancements, tags, and pack metadata once under src/main/rosetta-data, generateRosettaData produces the target resources during processResources.

plugins { id("net.rasanovum.rosetta.data") }
rosettaData {
    minecraftVersion.set("26.3")
    loader.set("fabric")
}

For applied scripts, put the plugin in the root plugins block with apply false, then use:

extra["rosetta.data.minecraft"] = project.property("deps.minecraft").toString()
apply(plugin = "net.rasanovum.rosetta.data")

The default source directory is relative to the consumer root, for shared Stonecutter sources. Override it through rosettaData.sourceDirectory or the root-relative rosetta.data.source bootstrap property. Minecraft defaults to deps.minecraft, loader defaults to the project name suffix. Explicit bootstrap properties are also available as rosetta.data.minecraft and rosetta.data.loader.

Source layout

src/main/rosetta-data/
  pack.json
  data/example/recipe/sticks.json
  data/example/advancement/root.json
  data/example/tags/block/path_block.json

Use the singular directory names from 1.21.1. Output goes to each target’s build/generated/rosetta-data, wired into processResources. The source tree is never rewritten. Ordinary resources can coexist, but the same output path in both trees fails the build. No recipe or advancement is synthesized unless you define it.

Tasks track definitions, Minecraft version, and loader as cache inputs. Removing a definition removes its generated output on the next generation. JSON comments, duplicate keys, invalid paths, and unsupported fields fail with the source file and target in the message.

Recipes

{
  "type": "minecraft:crafting_shaped",
  "pattern": ["#", "#"],
  "key": { "#": { "tag": "minecraft:planks" } },
  "result": { "id": "minecraft:stick", "count": 4 }
}

Supported types: crafting_shaped, crafting_shapeless, smelting, blasting, smoking, campfire_cooking, and stonecutting, in the vanilla namespace. Ingredients use {"item":"minecraft:stone"} or {"tag":"minecraft:planks"}, or nonempty lists of these objects. Lists containing tags work on 1.20.1 and 1.21.1, newer targets reject them because vanilla no longer supports that representation. Use a single tag or a target override in that case.

The plugin converts ingredient objects to strings for newer targets and handles recipe directories, result item versus id, and the old cooking/stonecutting result format. A legacy cooking recipe cannot produce a count other than one. Common category/group, shaped notification, and cooking experience/time fields are retained.

Custom serializers, smithing/transmute recipes, component-bearing results, and NBT require an explicit native target definition. Component payloads change independently of the enclosing recipe schema, this release does not guess their meaning.

Advancements

{
  "display": {
    "icon": { "id": "minecraft:oak_planks" },
    "title": { "text": "First planks" },
    "description": { "text": "Obtain two planks" },
    "background": "minecraft:textures/gui/advancements/backgrounds/stone.png"
  },
  "criteria": {
    "planks": {
      "trigger": "minecraft:inventory_changed",
      "conditions": {
        "items": [{ "items": "#minecraft:planks", "count": { "min": 2 } }]
      }
    }
  },
  "requirements": [["planks"]]
}

Supported triggers are inventory_changed, tick, and impossible. Inventory conditions support items predicates (IDs, ID lists, or a tag, with optional count bounds) and slots bounds. The plugin adapts the old item predicate tag/list form, icon field, background texture path, and advancement directory. Requirements are checked against criteria. Parent, rewards, and ordinary display settings remain available.

Text supports literal strings and basic text/translate components, including nested with/extra and styling. Complex predicates, entity/player conditions, component icons, interaction events in text, and other triggers need native target definitions. In particular, a renamed trigger that changed gameplay meaning is not silently substituted.

Tags

{ "replace": false, "values": ["minecraft:stone", { "id": "#example:optional", "required": false }] }

Use vanilla 1.21.1 registry folder names, such as block, item, and damage_type. The plugin handles the older directory names when generating 1.20.1 output. Values and optional references are preserved. The plugin does not verify registry existence or loader-specific custom tag semantics.

Target overrides

Use vanilla 1.21.1 JSON plus optional top-level $rosetta metadata:

{
  "type": "minecraft:crafting_shapeless",
  "ingredients": [{ "item": "minecraft:stone" }],
  "result": { "id": "minecraft:stone_button" },
  "$rosetta": {
    "overrides": {
      "1.20.1": { "group": "legacy_buttons" },
      "1.20.1-fabric": { "group": null }
    },
    "native": {
      "26.3": { "type": "example:custom_recipe", "custom_field": true }
    },
    "exclude": ["26.2-neoforge"]
  }
}

Selectors are an exact supported Minecraft version or that version followed by -fabric, -forge, or -neoforge. Version overrides apply first, then loader-specific overrides. overrides use the same 1.21.1 authoring format and are recursive merge patches applied before conversion: null deletes a field, arrays replace arrays. native supplies a complete target-native JSON body and bypasses schema conversion, it still uses the target directory mapping. Loader-specific native bodies replace version-wide native bodies. exclude omits the resource for the selected target. Metadata never enters the mod jar. Unsupported target selectors are errors.

Native definitions are an escape hatch, not a promise of runtime validity. Minecraft and the relevant mod serializer remain authoritative for their contents.

Pack metadata

Optional pack.json:

{ "description": "Example resources", "kind": "combined" }

Kinds are combined (default, for mod jars), data, and resources. Generated pack.mcmeta accounts for separate data/resource versions:

Minecraft	Data	Resources
1.19.2	10	9
1.20.1	15	15
1.21.1	48	34
26.1	101.1	84.0
26.2	107.1	88.0
26.3	121.0	97.1

Combined packs advertise the range spanning both pack types. For 1.21.1 this uses supported_formats, modern targets use min_format and max_format. Single-purpose packs advertise only their own format. This range serves the two pack types in one target jar, it does not claim that the generated data works on every intervening Minecraft release. pack.json has no target override metadata, target format rules belong in the plugin.

Notes

The plugin does not cover loot tables, worldgen, item models, arbitrary JSON transformations, or automatic registry validation (yet).

Resource-only library metadata

Apply net.rasanovum.rosetta.pack-metadata in a target build script and use project.extra["rosetta.packFormatFields"] when expanding a pack.mcmeta template’s format members. The plugin derives the Minecraft version and loader from the Stonecutter project name. This shares the data compiler’s verified version table without generating a datapack or changing source directories. For Forge 1.19.2 it includes resource format 9 and data format 10 as typed Forge fields.